ballast Ratio

[Roach1948]

Recently a friend bought a Contessa 32 (a Classic I was reminded) and then I got a lecture on how she survived Fastnet and the magic of her 50% ballast ratio.

Well, I might not have an ocean going yacht but my 1948 long keel sloop has a iron keel of one ton on 3 ton weight overall. Well that suggests to me a ballast ration 33%.
She was condemned as unseaworthy by my friend and I found it hard arguing my point.

The thing is that I am a long keeler and my water, batteries, engine and most storage in under the water line. Not to mention that long keel! I weigh more than a Bavaria 30 at only 22ft!

My question is: Being unsure how Ballast Ratio is worked out, are us classic long keelers disadvantaged by calculating keel weight alone? Surely stability has other factors (the keel shape/loading depth) and our forebearers knew a thing about this too?

 

[Peterduck]

I'm afraid that your friend is taking a simplistic view of a very complex subject. You are correct in assuming that whole boat displacement has a say in stability too. Our forebears learned in the grand university of Time At Sea. If it were up to ballast ratio alone, I'm afraid that your friend would also condemn the Bark 'Endeavour' as unseaworthy! The lighter that yachts get [in search of racing success] the more that ballast ratio becomes important. What is also important is how far over can a boat be lain before water penetrates below where it didn't orter be. Wide side-decks and small , narrow openings on the centre-line help in this. A high displacement/length ratio confers not only stability, but comfort too. A heavy boat will not heel to a breeze as easily as a light boat, and critics will claim that it takes a gale to get them moving. Well, when it comes to being at sea in a gale, would you rather be in a boat that is still carrying its normal sails, with perhaps the first reef in, or one that's down to a storm trysail?

Consider also the role of beam in all this. A plump Colin Archer redningskjoite [rescue boat] will stay out in all weathers, when
skinnier Metre yachts are on their beam ends. Lots of beam, however, makes a boat slow, so if you are heavily influenced by racing, you will eschew it. For myself, I'd rather have a yacht where I can heave to, close the hatch above me and brew up a cuppa when all hell is breaking loose outside. You can't do that if you're lying on the cabin sole so that you can't fall any further!
Peter.

 

[Roach1948]

I agree with everything you say, but these days it seems a simplistic percentage is what most people look at these days and I was wondering whether there is some mechanism to incorporate a classic yacht keel ballast shape - on handicap maybe - into ballast ratio terms a modern AWB will appreciate or even respect!

 

[Kristal]

Statistically speaking, we probably are, but hands up those of us who care? Are you planning to head across the Atlantic any time soon in your unsuitable boat? Is your friend, in his Contessa?

My boat clearly isn't ocean-going. Neither am I. Suits us.

I find arguments such as your friend's very irritating, when a largely academic point leads to criticism of someone elses pride and joy.

/<

 

[cliffordpope]

It seems to me a purely arbitrary distinction to count the bolt-on iron keel as "ballast" but to ignore other weight low down. As has been said, what about the engine? Or a water or fuel tank in the bilges? Does internal ballast such as pig-iron count as "ballast" in this formula?
Surely a more useful figure would be the angle of zero stability, or whatever it is called - the point when a boat stops having any self-righting moment, and capsizes.

 

[Salty John]

You might want to point out to your friend that in his report on the RYC-RORC Fastnet findings, Dale Nouse, editor of Cruising World magazine wrote:
"There was little indication of any tie between knockdowns and either ballast ratio or length/displacement ratios"

 

[Gordonmc]

Exactly.
The amount of internal ballast in my bilges must equate to around a third of the keel weight, but its described as "trimmable" which means the distribution can be changed if, for instance, a heavier engine is put in or additional fuel bunkerage is needed.
To ignore the pig iron in any calculation of ballast ratio would be daft... and so too would be to ignore other counter-weight, such as bunkerage or engine.
It seems a non-argument.

 

[grumpydog]

Kristal: "I find arguments such as your friend's very irritating, when a largely academic point leads to criticism of someone elses pride and joy."

Well put! At one time during my long search for a project to restore, I looked at a Dauntless. Lots of tooth-sucking. "I woulnd't go offshore with that," they said. I refrained from replying "I woulnd't go offshore with you", but did point out that the kind of sailing I had in mind, and the kind that he did at weekends, isn't offshore anyway. It's pottering around the coasts. And if a simple calculation of displacement ratio is taken on too general terms, it would be hard to explain how Ellen McArthur got around the world so quickly. That's an extreme example I know, but it does show the error in thinking very clearly. In fact, one might have said to her "I wouldn't go offshore in that"...

 

[Mirelle]

Just to get really technical...

...what your friend should be looking at is the area under the curve in the curve of righting moments.

Owners of long keeled older boats may choose to look at Tony Marchaj's book "Seaworthiness - the forgotten factor" for an extensive justification of their type of boat, with lots of sums, by a very emininent authority,

 

[Roach1948]

[ QUOTE ]
Kristal: "I find arguments such as your friend's very irritating, when a largely academic point leads to criticism of someone elses pride and joy."

Well I am not sure it was meant as an insult towards me. He has just started sailing and has small kids, so was genuinely concerned with seaworthiness.

After a peek at my classic, he was quietly impressed with the headroom (same as a Contessa) and all that gleaming wood and interior panelling, so maybe it was mini envious dig.

I am not bothered though as for me aesthetics are key. For him it is safety. I believe Oscar Wilde once said "A thing of beauty is a joy for life".

 

[grumpydog]

That quote was actually Keats. A hysterical misquote though, when one remembers that the Oscar Wilde quote on beauty is far more fitting to wooden boats:

"There is no true beauty without decay."

 

[Mirelle]

More technicality:

the line is in fact

"A thing of beauty is a joy for ever"

and is the first line of "Endymion" .

OK, so no guesses needed about what I read at University...

 

[Roach1948]

Haha, Well I suppose it was not a quote at all in the end! I like Oscar Wilde's one though, more appropriate to wooden boats indeed!

 

[keelbolts]

Here's a simple way to see that there's more to it than the ratio of ballast to wood. How stable would your boat be if, assuming you had a really strong rig, you put your lead at the top of your mast? Instantly, you can see there are other things to consider. Having said that, I think that, other things being equal, more ballast is generally better than less ballast.